The direct- and alternating-current characteristics of double-barrier diodes were used to monitor the large-scale annealing of defects in ion-implanted samples. Multi-stage annealing of defects was reflected by the stage-by-stage recovery of resonant tunnelling through ion-implanted diodes. The current-voltage characteristics of some implanted diodes, after very rapid annealing, were surprisingly similar to the as-grown characteristics, but the peak-current density was 2 orders of magnitude lower. This was attributed to the creation of small percolation paths of as-grown material during the initial stages of annealing; with these paths surrounding clusters of defects. A simple capacitance model, based upon the creation of these percolation paths, was shown to be consistent with the capacitance-voltage data. The concept that small-area percolation paths of as-grown material were created within ion-implanted samples during very rapid annealing was supported by the observation of very low bias resonant tunnelling and single-electron switching at 4.2K.

K.Billen, M.J.Kelly, R.M.Gwilliam, S.Hutchinson, L.Eaves, M.Henini, T.J.Foster: Semiconductor Science and Technology, 1997, 12[10], 1273-81